MTA is switching their bridges to LED, I haven't been to NYC at night since before Sandy hit so no idea, but I do know that in 2012 they were running a lot of HPS and Mercury. As funds become available I would not be surprised to see NYC start changing more lighting to LED to reduce energy costs. They are also wanting to get rid of one of the nuclear plants (Indian Point IIRC) so that will also have some say in the desire to increase efficiency.

Manhattan will probably see upgrades first. Queens and Brooklyn will probably be after Manhattan. Bronx and Staten Island will probably be last (Bronx due to being poor, Staten Island due to lower density).

Here is some information on Street lights in The City Of New York. Starting in 2007, all street lights were changed to 100 and 150 watt HPS Cooper luminaires equipped with electronic ballasts. Whatever mercury lights ( no more than a few hundred,if that many) still existing were replaced. In 2012, a test installation of LED fixtures was made on the Honeywell Street bridge in Long Island City.(Google Honeywell Bridge LED). This went well,so the first contract awarded was to replace all highway and parkway lights. The contractors purchase the luminaires from manufacturers on the list approved by The NYCDOT. The contractor chose Cree 101 watt luminaires for the highway replacements.The next major contract was for what was called by the City "The Vision Zero" program. In an attempt to decrease pedestrian fatalities, thousands of street lights were added at intersections,mounted on existing poles at a 90 degree angle to the original luminaire. For this contract Cooper Verdeon 77watt luminaires were used.For Brooklyn The contractor chose Cooper Verdeon luminaires in 77 and 91 watt versions.Brooklyn is completed. Queens was next and the contractor,Welsbach Electric,chose Philips Lumec in 108 and 64 watt versions. Queens is nearly completed. The lights on my street were changed on tuesday. The light in front of my house was a 150watt HPS and was replaced with a 64 watt LED. It's quite astounding to me how well the street is lit, with the light being thrown up and down the street much better than I expected. The only difference is the loss of the stray light that lit up the yards. I was able to purchase a copy of the next contract, for The Bronx,Manhattan,and Staten Island.Welsbach was again the low bidder. Purchase and install 86,000 luminaires and photocontrols. Low bid ,a little over $17,000,000. That's about $200 per luminaire. Work to start Jan. of 2017. In case you think that's a high price,consider this. The contractor must use Local 3 "A" construction electricians. The salary is $54.00 an hour,with an additional benefit package of $55.00 an hour. It's no wonder that according to one of the guys I talked to, that the company is trying to get them to change 32 luminaires per day.